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In the first stage of the Calvin cycle, a CO2 molecule is incorporated into one of two three-carbon molecules (glyceraldehyde 3-phosphate or G3P), where it uses up two molecules of ATP and two molecules of NADPH, which had been produced in the light-dependent stage. The three steps involved are: The enzyme RuBisCO cata... | Wikipedia - Calvin Cycle - Steps |
The CO2 that is captured by enediol in second step produces an unstable six-carbon compound called 2-carboxy 3-keto 1,5-biphosphoribotol (CKABP) (or 3-keto-2-carboxyarabinitol 1,5-bisphosphate) that immediately splits into 2 molecules of 3-phosphoglycerate (also written as 3-phosphoglyceric acid, PGA, 3PGA, or 3-PGA), ... | Wikipedia - Calvin Cycle - Steps |
(However, note that two 3-PGAs are produced for every CO2 that enters the cycle, so this step utilizes two ATP per CO2 fixed.) The enzyme glyceraldehyde 3-phosphate dehydrogenase catalyses the reduction of 1,3BPGA by NADPH (which is another product of the light-dependent stage). Glyceraldehyde 3-phosphate (also called ... | Wikipedia - Calvin Cycle - Steps |
Again, two NADPH are utilized per CO2 fixed.The next stage in the Calvin cycle is to regenerate RuBP. Five G3P molecules produce three RuBP molecules, using up three molecules of ATP. Since each CO2 molecule produces two G3P molecules, three CO2 molecules produce six G3P molecules, of which five are used to regenerate ... | Wikipedia - Calvin Cycle - Steps |
The regeneration stage can be broken down into a series of steps. Triose phosphate isomerase converts all of the G3P reversibly into dihydroxyacetone phosphate (DHAP), also a 3-carbon molecule. | Wikipedia - Calvin Cycle - Steps |
Aldolase and fructose-1,6-bisphosphatase convert a G3P and a DHAP into fructose 6-phosphate (6C). A phosphate ion is lost into solution. Then fixation of another CO2 generates two more G3P. | Wikipedia - Calvin Cycle - Steps |
F6P has two carbons removed by transketolase, giving erythrose-4-phosphate (E4P). The two carbons on transketolase are added to a G3P, giving the ketose xylulose-5-phosphate (Xu5P). E4P and a DHAP (formed from one of the G3P from the second CO2 fixation) are converted into sedoheptulose-1,7-bisphosphate (7C) by aldolas... | Wikipedia - Calvin Cycle - Steps |
Sedoheptulose-1,7-bisphosphatase (one of only three enzymes of the Calvin cycle that are unique to plants) cleaves sedoheptulose-1,7-bisphosphate into sedoheptulose-7-phosphate, releasing an inorganic phosphate ion into solution. Fixation of a third CO2 generates two more G3P. The ketose S7P has two carbons removed by ... | Wikipedia - Calvin Cycle - Steps |
This leaves one G3P as the product of fixation of 3 CO2, with generation of three pentoses that can be converted to Ru5P. R5P is converted into ribulose-5-phosphate (Ru5P, RuP) by phosphopentose isomerase. Xu5P is converted into RuP by phosphopentose epimerase. | Wikipedia - Calvin Cycle - Steps |
Finally, phosphoribulokinase (another plant-unique enzyme of the pathway) phosphorylates RuP into RuBP, ribulose-1,5-bisphosphate, completing the Calvin cycle. This requires the input of one ATP.Thus, of six G3P produced, five are used to make three RuBP (5C) molecules (totaling 15 carbons), with only one G3P available... | Wikipedia - Calvin Cycle - Steps |
This requires nine ATP molecules and six NADPH molecules per three CO2 molecules. The equation of the overall Calvin cycle is shown diagrammatically below. | Wikipedia - Calvin Cycle - Steps |
RuBisCO also reacts competitively with O2 instead of CO2 in photorespiration. The rate of photorespiration is higher at high temperatures. Photorespiration turns RuBP into 3-PGA and 2-phosphoglycolate, a 2-carbon molecule that can be converted via glycolate and glyoxalate to glycine. | Wikipedia - Calvin Cycle - Steps |
Via the glycine cleavage system and tetrahydrofolate, two glycines are converted into serine plus CO2. Serine can be converted back to 3-phosphoglycerate. Thus, only 3 of 4 carbons from two phosphoglycolates can be converted back to 3-PGA. | Wikipedia - Calvin Cycle - Steps |
It can be seen that photorespiration has very negative consequences for the plant, because, rather than fixing CO2, this process leads to loss of CO2. C4 carbon fixation evolved to circumvent photorespiration, but can occur only in certain plants native to very warm or tropical climates—corn, for example. Furthermore, ... | Wikipedia - Calvin Cycle - Steps |
In the first stage of the programme, natural uranium fueled pressurised heavy water reactors (PHWR) produce electricity while generating plutonium-239 as by-product. PHWRs was a natural choice for implementing the first stage because it had the most efficient reactor design in terms of uranium utilisation, and the exis... | Wikipedia - Bhabha Atomic Research Centre - Stage I – Pressurised Heavy Water Reactor |
In the first stage, the investigator attempts to rule out drugs that have no or little biologic activity. For example, the researcher may specify that a drug must have some minimal level of activity, say, in 20% of participants. If the estimated activity level is less than 20%, the researcher chooses not to consider th... | Wikipedia - Phases of clinical research - Example: cancer design |
A typical study for ruling out a 20% or lower response rate enters 14 participants. If no response is observed in the first 14 participants, the drug is considered not likely to have a 20% or higher activity level. The number of additional participants added depends on the degree of precision desired, but ranges from 1... | Wikipedia - Phases of clinical research - Example: cancer design |
In the first stages of infection, conserved molecules from the fungal pathogen's cell wall, such as polysaccharides and chitin, are recognised by membrane-localised pattern recognition receptors (PRRs) on the plant host's side. Such conserved molecules are generally described as pathogen-associated molecular patterns (... | Wikipedia - Fungal effectors - Plant pathogenic fungi |
In the first stages of insurrection, much of an army's work is "soft" – working in conjunction with civil authorities in psychological operations, propaganda, counter-organizing, so-called "hearts and minds." If the conflict progresses, possibly into armed clashes, the role develops with the addition of the identificat... | Wikipedia - Low intensity conflict - Stages |
In the first stages of the development of the Melomics system, Iamus composed Opus one (on October 15, 2010), arguably the first fragment of professional contemporary classical music ever composed by a computer in its own style, rather than attempting to emulate the style of existing composers. The first full compositi... | Wikipedia - Melomics - Iamus album |
In the first step in the reproductive cycle for Mozambique tilapia, males excavate a nest into which a female can lay her eggs. After the eggs are laid, the male fertilizes them. Then the female stores the eggs in her mouth until the fry hatch; this act is called mouthbrooding. One of the main reasons behind the aggres... | Wikipedia - Mozambique tilapia - Reproduction |
The designation of Mozambique tilapias as an invasive species rests on their life-history traits: Tilapias exhibit high levels of parental care as well as the capacity to spawn multiple broods through an extended reproductive season, both contributing to their success in varying environments. In the lek system, males c... | Wikipedia - Mozambique tilapia - Reproduction |
Dominant males also build larger nests for the spawn. During courtship rituals, acoustic communication is widely used by the males to attract females. Studies have shown that females are attracted to dominant males who produce lower peak frequencies as well as higher pulse rates. | Wikipedia - Mozambique tilapia - Reproduction |
At the end of mating, males guard the nest while females take both the eggs and the sperm into their mouth. Due to this, Mozambique tilapias can occupy many niches during spawning since the young can be transported in the mouth. These proficient reproductive strategies may be the cause behind their invasive tendencies. | Wikipedia - Mozambique tilapia - Reproduction |
Male Mozambique tilapias synchronize breeding behavior in terms of courtship activity and territoriality in order to take advantage of female spawning synchrony. One of the costs associated with this synchronization is the increase in competition among males, which are already high on the dominance hierarchy. | Wikipedia - Mozambique tilapia - Reproduction |
As a result, different mating tactics have evolved in these species. Males may mimic females and sneak reproduction attempts when the dominant male is occupied. Likewise, another strategy for males is to exist as a floater, travelling between territories in an attempt to find a mate. Nevertheless, it is the dominant ma... | Wikipedia - Mozambique tilapia - Reproduction |
In the first step of extraction, the oil must be separated from the rest of the algae. The simplest method is mechanical crushing. When algae is dried it retains its oil content, which then can be "pressed" out with an oil press. Different strains of algae warrant different methods of oil pressing, including the use of... | Wikipedia - Open pond - Physical extraction |
Many commercial manufacturers of vegetable oil use a combination of mechanical pressing and chemical solvents in extracting oil. This use is often also adopted for algal oil extraction. Osmotic shock is a sudden reduction in osmotic pressure, this can cause cells in a solution to rupture. | Wikipedia - Open pond - Physical extraction |
Osmotic shock is sometimes used to release cellular components, such as oil. Ultrasonic extraction, a branch of sonochemistry, can greatly accelerate extraction processes. | Wikipedia - Open pond - Physical extraction |
Using an ultrasonic reactor, ultrasonic waves are used to create cavitation bubbles in a solvent material. When these bubbles collapse near the cell walls, the resulting shock waves and liquid jets cause those cells walls to break and release their contents into a solvent. Ultrasonication can enhance basic enzymatic ex... | Wikipedia - Open pond - Physical extraction |
In the first step of heterochromatin formation, RNAP IV couples with an RNA-dependent RNA polymerase known as RDR2 to make a double stranded precursor to siRNA. Next, DICER-Like Protein 3 (DLP3), an enzyme which slices double stranded RNA substrates, cleaves the double stranded precursor into siRNAs that are each 24 nu... | Wikipedia - RNA polymerase IV - Mechanism |
In the first step of nixtamalization, kernels of dried maize are cooked in an alkaline solution at or near the mixture's boiling point. After cooking, the maize is steeped in the cooking liquid for a period. The length of time for which the maize is boiled and soaked varies according to local traditions and the type of... | Wikipedia - Nixtamalization - Cooking |
Because plant cell wall components, including hemicellulose and pectin, are highly soluble in alkaline solutions, the kernels soften and their pericarps (hulls) loosen. The grain hydrates and absorbs calcium or potassium (depending on the alkali used) from the cooking solution. Starches swell and gelatinize, and some s... | Wikipedia - Nixtamalization - Cooking |
In the first step of quinine biosynthesis, the enzyme strictosidine synthase catalyzes a stereoselective Pictet–Spengler reaction between tryptamine and secologanin to yield strictosidine. Suitable modification of strictosidine leads to an aldehyde. Hydrolysis and decarboxylation would initially remove one carbon from ... | Wikipedia - Quinine Sulfate - Biosynthesis |
Ring opening in the indole heterocyclic ring could generate new amine and keto functions. The new quinoline heterocycle would then be formed by combining this amine with the aldehyde produced in the tryptamine side-chain cleavage, giving cinchonidinone. For the last step, hydroxylation and methylation gives quinine. | Wikipedia - Quinine Sulfate - Biosynthesis |
In the first step of the biosynthetic pathway, L-tyrosine is converted to L-3,4-dihydroxyphenylalanine (L-dopa) by 3-hydroxylation by a cytochrome P450 enzyme. For dopa, the biosynthesis branches: a) on the one hand, its oxidation occurs by a CYP enzyme to cyclo-dopa; (b) on the other hand, the aromatic ring of dopa is... | Wikipedia - Betalain - Biosynthesis |
In the first step of the catalyzed reaction, citrulline attacks the α-phosphate of ATP to form citrulline adenylate, a reactive intermediate. The attachment of AMP to the ureido (urea-like) group on citrulline activates the carbonyl center for subsequent nucleophilic attack. This activation facilitates the second step,... | Wikipedia - Argininosuccinate synthase - Mechanism |
Attack by aspartate is the rate-limiting step of the reaction. This step produces free AMP and L-argininosuccinate.Thermodynamically, adenylation of the citrulline ureido group is more favorable than the analogous phosphorylation. Additionally, attack by citrulline at the α-phosphate of ATP produces an equivalent of py... | Wikipedia - Argininosuccinate synthase - Mechanism |
In the first step of the mechanism, an α-proton is removed by a strong base, resulting in the formation of an enolate anion, which is made relatively stable by the delocalization of electrons. Next, the carbonyl carbon of the (other) ester is nucleophilically attacked by the enolate anion. The alkoxy group is then elim... | Wikipedia - Claisen condensation - Mechanism |
The newly formed β-keto ester or β-diketone is then isolated. Note that the reaction requires a stoichiometric amount of base as the removal of the doubly α-proton thermodynamically drives the otherwise endergonic reaction. That is, Claisen condensation does not work with substrates having only one α-hydrogen because o... | Wikipedia - Claisen condensation - Mechanism |
In the first step of the mechanism, the glycosyl bromide reacts with silver carbonate upon elimination of silver bromide and the silver carbonate anion to the oxocarbenium ion. From this structure a dioxolanium ring is formed, which is attacked by methanol via an SN2 mechanism at the carbonyl carbon atom. This attack l... | Wikipedia - Koenigs–Knorr reaction - Mechanism |
After deprotonation of the intermediate oxonium, the product glycoside is formed. The reaction can also be applied to carbohydrates with other protecting groups. In the oligosaccharide synthesis in place of the methanol other carbohydrates are used, which have been modified with protective groups in such a way that onl... | Wikipedia - Koenigs–Knorr reaction - Mechanism |
In the first step of the porphyrin biosynthesis pathway, porphobilinogen is generated from aminolevulinate (ALA) by the enzyme ALA dehydratase. | Wikipedia - Porphobilinogen - Biosynthesis |
In the first step of the production process, Al2O3 (Aluminium oxide) flakes with a very smooth surface are formed. The flakes are produced using a crystal growth process. They are formed in the corundum structure (α-Al2O3). The desired flake shape is achieved by controlled crystal growth in the axial and equatorial dir... | Wikipedia - Alumina effect pigment - Production process |
The color purity and transparency of the effect pigments obtained by coating the Al2O3 flakes with metal oxides can be attributed to the synthesis procedure yielding single-crystalline thin flakes The coating of the alumina platelets with high-refractive metal oxides, such as with titanium dioxide and iron(III) oxide l... | Wikipedia - Alumina effect pigment - Production process |
In the first step of the reaction mechanism a proton adds to a carbon atom with high electron density therefore by preference to C2 or C4 of naphthol (1). This leads to resonance stabilized adducts 1a-1e. De-aromatization of the first ring of the naphthalene system occurs at the expense of 25 kcal/mol. In the next step... | Wikipedia - Bucherer reaction - Mechanism |
This results in the formation of 3a which tautomerizes to the more stable 3b to the sulfonic acid of tetralone. A nucleophilic addition follows of the amine with formation of 4a and its tautomer 4b loses water to form the resonance stabilized cation 5a. This compound is deprotonated to the imine 5b or the enamine 5c bu... | Wikipedia - Bucherer reaction - Mechanism |
The enamine eliminates sodium bisulfite with formation of naphthylamine 6. It is important to stress that this is a reversible reaction. The reaction is summarized as follows: The Bucherer carbazole synthesis is a related reaction. == References == | Wikipedia - Bucherer reaction - Mechanism |
In the first step of the reaction mechanism for the synthesis of a 5-aminothiazole from an α-aminonitrile and carbon disulphide, a lone pair on the nitrogen of the α-aminonitrile performs a nucleophilic attack on the slightly electropositive carbon of carbon disulfide. This addition reaction pushes electrons from the c... | Wikipedia - Cook–Heilbron thiazole synthesis - Mechanism |
This cyclization forms a 5-imino-2-thione thiazolidine compound that undergoes a tautomerization when a base, such as water, abstracts the hydrogens at positions 3 and 4. The electrons from the carbon-hydrogen sigma bond are pushed back into the thiazole ring, forming two new double bonds with the adjacent carbon atoms... | Wikipedia - Cook–Heilbron thiazole synthesis - Mechanism |
In the first step of the reaction mechanism the precursor molecule 2-nitrobenzaldehyde 4 is protonated, often by sulfuric acid, to intermediate 5, followed by an electrophilic attack to benzene (other arenes can be used as well). The resulting benzhydrol 6 cyclisizes to 7 and finally to compound 8. Treatment of this in... | Wikipedia - Lehmstedt–Tanasescu reaction - Reaction mechanism |
The N-nitroso group is removed by an acid in the final step. The procedure is an example of a one-pot synthesis. == References == | Wikipedia - Lehmstedt–Tanasescu reaction - Reaction mechanism |
In the first step of the reaction mechanism, the peroxyacid protonates the oxygen of the carbonyl group. This makes the carbonyl group more susceptible to be attacked by the peroxyacid. Next, the peroxyacid attacks the carbon of the carbonyl group forming what is known as the Criegee intermediate. Through a concerted m... | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
This migration step is thought to be the rate determining step. Finally, deprotonation of the oxocarbenium ion produces the ester. The products of the Baeyer–Villiger oxidation are believed to be controlled through both primary and secondary stereoelectronic effects. | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
The primary stereoelectronic effect in the Baeyer–Villiger oxidation refers to the necessity of the oxygen-oxygen bond in the peroxide group to be antiperiplanar to the group that migrates. This orientation facilitates optimum overlap of the 𝛔 orbital of the migrating group to the 𝛔* orbital of the peroxide group. Th... | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
This allows for optimum overlap of the oxygen nonbonding orbital with the 𝛔* orbital of the migrating group. This migration step is also (at least in silico) assisted by two or three peroxyacid units enabling the hydroxyl proton to shuttle to its new position. | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
The migratory ability is ranked tertiary > secondary > aryl > primary. Allylic groups are more apt to migrate than primary alkyl groups but less so than secondary alkyl groups. Electron-withdrawing groups on the substituent decrease the rate of migration. | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
There are two explanations for this trend in migration ability. One explanation relies on the buildup of positive charge in the transition state for breakdown of the Criegee intermediate (illustrated by the carbocation resonance structure of the Criegee intermediate). Keeping this structure in mind, it makes sense that... | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
The higher the degree of substitution, the more stable a carbocation generally is. Therefore, the tertiary > secondary > primary trend is observed. Another explanation uses stereoelectronic effects and steric arguments. | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
As mentioned, the substituent that is antiperiplanar to the peroxide group in the transition state will migrate. This transition state has a gauche interaction between the peroxyacid and the non-migrating substituent. If the bulkier group is placed antiperiplanar to the peroxide group, the gauche interaction between th... | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
Thus, it is the bulkier group that will prefer to be antiperiplanar to the peroxide group, enhancing its aptitude for migration. The migrating group in acyclic ketones, usually, is not 1° alkyl group. However, they may be persuaded to migrate in preference to the 2° or 3° groups by using CF3CO3H or BF3 + H2O2 as reagen... | Wikipedia - Baeyer-Villiger oxidation - Reaction mechanism |
In the first step of this condensation reaction, the amine group of HAP forms a Schiff base with the ketone group of DXP. The hydroxyl group on C4 of DXP is eliminated, forming an enol. The enol eliminates the phosphate derived from DXP, and water is added to the resulting double bond to reform the enol. This enol then... | Wikipedia - Pyridoxine 5'-phosphate synthase - Mechanism |
A deprotonation causes the ring to aromatize, completing the synthesis of pyridoxine-5'-phosphate. 3-hydroxy-1-aminoacetone phosphate is unstable, so the reaction mechanism cannot be confirmed directly. Nonetheless, 14C and 18O isotopic labeling experiments, as well as structural studies, support the mechanism shown he... | Wikipedia - Pyridoxine 5'-phosphate synthase - Mechanism |
In the first step of this mechanism, the alcohol (1) coordinates to the aluminium to form a complex (3), which then, in the second step, gets deprotonated by an alkoxide ion (4) to generate an alkoxide intermediate (5). In the third step, both the oxidant acetone (7) and the substrate alcohol are bound to the aluminium... | Wikipedia - Oppenauer oxidation - Mechanism |
In the first step of this process, the slag or other raw materials containing metal values of interest, e.g. chromium, is dissolved into the molten salt phase at a suitable temperature. A suitable flux must be found in order to achieve the dissolution of oxides. According to the Fajans' rules, AlCl3, as a covalent meta... | Wikipedia - Salt extraction process - Description |
AlCl3 was proved indeed to be a powerful fluxing agent in this regard.In the second step, the salt phase is subjected to electrolysis in order to recover the metal of interest as a cathode deposit. The salt melt used for extraction can be recycled. The metals can be selectively electrodeposited from the salt melt. | Wikipedia - Salt extraction process - Description |
There is also the option of aqueous processing of the salt phase containing the metal values. The process can design to be continuous by combining the two steps. The anode off-gas from electrolysis, Cl2 can be reused for accentuating the dissolution of the raw materials. On the other hand, the residue after processing,... | Wikipedia - Salt extraction process - Description |
In the first step the hydrocarbon fuel is reformed to syngas in the reformer which is then used to reduce the iron oxide (magnetite—Fe3O4) to iron (wüstite—FeO), in the second step steam is utilized to re-oxidise the iron into magnetite and hydrogen. The iron oxide pellets are placed in a pelletbed and have a service l... | Wikipedia - Reformer sponge iron cycle - Reformer sponge iron cycle |
In the first step the polymers are processed by means of common techniques, such as injection or extrusion, thermoforming, at a temperature (THigh) at which the polymer melts, obtaining a final shape which is called "permanent" shape. The next step is called system programming and involves heating the sample to a trans... | Wikipedia - Thermally induced shape-memory effect (polymers) - Description of the effect on polymers |
The final step of the effect involves the recovery of the permanent shape. The sample is heated to the transition temperature (TTrans) and within a short time the recovery of the permanent shape is observed. This effect is not a natural property of the polymer, but results from proper programming of the system with the... | Wikipedia - Thermally induced shape-memory effect (polymers) - Description of the effect on polymers |
In the first step, a delocalized allyloxocarbenium ion (2) is formed, typically with the aid of a Lewis acid like indium(III) chloride or boron trifluoride. This ion reacts in situ with an alcohol, yielding a mixture of the α (3) and β (4) anomers of the 2-glycoside, with the double bond shifted to position 3,4. | Wikipedia - Ferrier rearrangement - Mechanism |
In the first step, borane (BH3) adds to the double bond, transferring one of the hydrogen atoms to the carbon adjacent to the one that becomes bonded to the boron. This hydroboration is repeated two additional times, successively reacting each B–H bond so that three alkenes add to each BH3. The resulting trialkylborane... | Wikipedia - Hydroboration–oxidation reaction - Hydroboration step |
The boron reagent is converted to boric acid. The reaction was originally described by H.C. | Wikipedia - Hydroboration–oxidation reaction - Hydroboration step |
Brown in 1957 for the conversion of 1-hexene into 1-hexanol. Knowing that the group containing the boron will be replaced by a hydroxyl group, it can be seen that the initial hydroboration step determines the regioselectivity. Hydroboration proceeds in an anti-Markovnikov manner. | Wikipedia - Hydroboration–oxidation reaction - Hydroboration step |
The reaction sequence is also stereospecific, giving syn addition (on the same face of the alkene): the hydroboration is syn-selective and the oxidation replaces the boron with hydroxyl having the same geometric position. Thus 1-methylcyclopentene reacts with diborane predominantly to give trans-1-hydroxy-2-methylcyclo... | Wikipedia - Hydroboration–oxidation reaction - Hydroboration step |
This means that one mole of hydroborane will undergo the reaction with three moles of alkene. Furthermore, it is not necessary for the hydroborane to have more than one hydrogen. For example, reagents of the type R2BH are commonly used, where R can represents the remainder of the molecule. Such modified hydroboration r... | Wikipedia - Hydroboration–oxidation reaction - Hydroboration step |
In the first step, holo-retinol binding protein (holo-RBP; simply means RBP bound to retinol, i.e. the RBP-ROH complex) binds to the extracellular portion of STRA6. This facilitates the release of retinol through the transporter. ROH is then transferred to cellular retinol binding protein 1 (CRBP1), an intracellular ac... | Wikipedia - Vitamin A receptor - Overview |
This phosphorylation enables the extension of the CBL further into the cell. Holo-CRBP-I, leaves the CBL and is replaced by apo-CRBP-I (unbound). Holo-CRBP-I will continue to the Endoplasmic Reticulum (ER) where lecithin retinol acyltransferase (LRAT) is bound. | Wikipedia - Vitamin A receptor - Overview |
ROH is released to LRAT which will convert retinol into retinylesters. Following the release of holo-CRBP-I from intercellular STRA6, STAT5 is recruited to STRA6 phosphorylated Y643 region where it is then phosphorylated by JAK2. This phosphorylation activates STAT5 which then makes its way to the nucleus to induce exp... | Wikipedia - Vitamin A receptor - Overview |
In the first step, manganese(II) sulphate (at 48% of the total volume) is added to an environmental water sample. Next, potassium iodide (15% in potassium hydroxide 70%) is added to create a pinkish-brown precipitate. In the alkaline solution, dissolved oxygen will oxidize manganese(II) ions to the tetravalent state. 2... | Wikipedia - Winkler test for dissolved oxygen - Chemical processes |
There is some uncertainty about whether the oxidised manganese is tetravalent or trivalent. Some sources claim that Mn(OH)3 is the brown precipitate, but hydrated MnO2 may also give the brown colour. 4 Mn(OH)2(s) + O2(aq) + 2 H2O → 4 Mn(OH)3(s)The second part of the Winkler test reduces (acidifies) the solution. | Wikipedia - Winkler test for dissolved oxygen - Chemical processes |
The precipitate will dissolve back into solution as the H+ reacts with the O2− and OH− to form water. MnO(OH)2(s) + 4 H+(aq) → Mn4+(aq) + 3 H2O(l)The acid facilitates the conversion by the brown, Manganese-containing precipitate of the Iodide ion into elemental Iodine. The Mn(SO4)2 formed by the acid converts the iodid... | Wikipedia - Winkler test for dissolved oxygen - Chemical processes |
In the first step, sodium chloride is treated with sulfuric acid in the Mannheim process. This reaction produces sodium sulfate (called the salt cake) and hydrogen chloride: 2 NaCl + H2SO4 → Na2SO4 + 2 HClThis chemical reaction had been discovered in 1772 by the Swedish chemist Carl Wilhelm Scheele. Leblanc's contribut... | Wikipedia - LeBlanc process - Chemistry |
First is the carbothermic reaction whereby the coal, a source of carbon, reduces the sulfate to sulfide: Na2SO4 + 2 C → Na2S + 2 CO2In the second stage, is the reaction to produce sodium carbonate and calcium sulfide. This mixture is called black ash. | Wikipedia - LeBlanc process - Chemistry |
Na2S + CaCO3 → Na2CO3 + CaSThe soda ash is extracted from the black ash with water. Evaporation of this extract yields solid sodium carbonate. This extraction process was termed lixiviation. | Wikipedia - LeBlanc process - Chemistry |
In the first step, sulfur is burned to produce sulfur dioxide. S(s) + O2 → SO2The sulfur dioxide is oxidized to sulfur trioxide by oxygen in the presence of a vanadium(V) oxide catalyst. This reaction is reversible and the formation of the sulfur trioxide is exothermic. 2 SO2 + O2 ⇌ 2 SO3The sulfur trioxide is absorbed... | Wikipedia - Oil of vitriol - Contact process |
In the first step, sulfur is burned to produce sulfur dioxide: S + O2 → SO2 (−297 kJ/mol)or, alternatively, hydrogen sulfide (H2S) gas is incinerated to SO2 gas: 2 H2S + 3 O2 → 2 H2O + 2 SO2 (−1036 kJ/mol)The sulfur dioxide then oxidized to sulfur trioxide using oxygen with vanadium(V) oxide as catalyst. 2 SO2 + O2 ⇌ 2... | Wikipedia - Battery acid - Wet sulfuric acid process |
In the first step, the amino group on the aniline (1) attacks the carbonyl of the ethyl oxomalonate (2). A proton from the nitrogen is extracted by the oxygen and an alcohol group forms (3). The carbonyl re-forms to make a keto group and an ethanol molecule leaves (4). Next, a ring closing reaction occurs by the bond f... | Wikipedia - Martinet dioxindole synthesis - Proposed mechanism |
After a proton transfer (6), an isomerization or a hydride shift occurs and aromaticity is restored to the six-membered ring (7). In the presence of base, the ester is hydrolyzed, ethanol is lost (8) and a decarboxylation occurs (9). The resulting product is the desired dioxindole (10).In the presence of oxygen, dioxi... | Wikipedia - Martinet dioxindole synthesis - Proposed mechanism |
In the first step, the antiprotons obtained from the LEAR entered the TRAP apparatus. They were immediately slowed down using the degrader foils. The first penning trap was used to the accumulate the entering antiprotons. While the second trap, located very close to the first one was used for the precision measurements... | Wikipedia - TRAP experiment - Experimental setup |
The number of antiprotons entering the degrader foils were counted using a scintillating device. A number of antiprotons coming out from the degrader foils were observed using an attached detector. The apparatus was cooled down to the liquid helium temperature for these measurements.The penning traps used strong magnet... | Wikipedia - TRAP experiment - Experimental setup |
The issue with storing antiprotons was that they required very stringent vacuum conditions, otherwise they would easily interact with the gas atoms in the medium and annihilate quickly. The TRAP collaboration achieved vacuum pressure as low as 10 − 14 T o r r {\displaystyle \mathrm {10^{-14}Torr} } , with less than 1 a... | Wikipedia - TRAP experiment - Experimental setup |
In the first step, the halogen dis-proportionates in the presence of hydroxide to give the halide and hypohalite. Br 2 + 2 OH − ⟶ Br − + BrO − + H 2 O {\displaystyle {\ce {Br2 + 2 OH- -> Br- + BrO- + H2O}}} If a secondary alcohol is present, it is oxidized to a ketone by the hypohalite: If a methyl ketone is present, i... | Wikipedia - Iodoform reaction - Mechanism |
The enolate undergoes electrophilic attack by the hypohalite (containing a halogen with a formal +1 charge). 2. When the α(alpha) position has been exhaustively halogenated, the molecule undergoes a nucleophilic acyl substitution by hydroxide, with −CX3 being the leaving group stabilized by three electron-withdrawing g... | Wikipedia - Iodoform reaction - Mechanism |
In the first step, the protein of interest (POI) is cross-linked with the DNA site it binds to in an in vitro environment. Usually this is done by a gentle formaldehyde fixation that is reversible with heat. Then, the cells are lysed and the DNA is sheared by sonication or using micrococcal nuclease. | Wikipedia - ChIP-on-chip - Wet-lab portion of the workflow |
This results in double-stranded chunks of DNA fragments, normally 1 kb or less in length. Those that were cross-linked to the POI form a POI-DNA complex. In the next step, only these complexes are filtered out of the set of DNA fragments, using an antibody specific to the POI. | Wikipedia - ChIP-on-chip - Wet-lab portion of the workflow |
The antibodies may be attached to a solid surface, may have a magnetic bead, or some other physical property that allows separation of cross-linked complexes and unbound fragments. This procedure is essentially an immunoprecipitation (IP) of the protein. This can be done either by using a tagged protein with an antibod... | Wikipedia - ChIP-on-chip - Wet-lab portion of the workflow |
The cross-linking of POI-DNA complexes is reversed (usually by heating) and the DNA strands are purified. For the rest of the workflow, the POI is no longer necessary. After an amplification and denaturation step, the single-stranded DNA fragments are labeled with a fluorescent tag such as Cy5 or Alexa 647. Finally, th... | Wikipedia - ChIP-on-chip - Wet-lab portion of the workflow |
In the first step, the receiver looks up the sedamo address code of the destination address. This code is forwarded to the sender. In the second step, the sender uses the code to print out the foreign address in an international format (as recommended by the Universal Postal Union). The sedamo system automatically gene... | Wikipedia - Service d'adresse mondial - Usage |
In the first study that looked at the gene cluster for tirandamycin production, Carlson et al. used primers specific for ketosynthase (KS) domains and CYP450 enzymes to probe the DNA of Streptomyces sp. 307-9, a previously determined producer of various tirandamycin analogues. They found that the tirandamycin gene clus... | Wikipedia - Tirandamycin - Biosynthesis |
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